A known channeled structural member consists of a rectangular metal member having in one face a longitudinal slot bordered by inwardly projecting flanges. In the use of this channeled structural member, fittings of various kinds are secured to the slotted face by arranging within the channel a fastener adapted to cooperate with a screw or bolt passing through the fitting and into the fastener.
Variations of fasteners for this purpose are described in U.S. Pat. No. 3,483,910 to LaLonde et al. One variation has various arrangements mounted on the top surface of the fastener for holding the fastener against the channel flanges. Another variation has a square configuration with upper portions of the corners removed to provide landings for engaging the channel flanges and slots for receiving an indexing tool to facilitate alignment of the fastener.
Another variation, described in U.S. Pat. No. 2,696,139 to Attwood, is provided with grooves equispaced with the inturned flanges of the above-mentioned channel and provided with teeth in the grooves. The fastener is also provided with a spring to hold the fastener against the channel flanges prior to affixing parts to the channel member. A variation is described in U.S. Pat. No. 3,049,161 to Attwood. This variation has teeth in a groove on one side of the fastener surface and a sharp edge on the other side thereof. U.S. Pat. No. 3,053,355 to Attwood describes a fastener with sharp edges on both sides of the fastener for gripping the channel flanges.
Other references which disclose fasteners for securing parts to channel members are U.S. Pat. No. 3,493,025 of LaLonde et al., U.S. Pat. No. 4,146,074 of Kowalski, and U.S. Pat. No. 4,285,379 of Kowalski.
The many variations of fasteners for securing fittings to a channeled structural member have various features, but none have provisions for properly positioning a given fastener in channeled structural members having different widths between the side walls but having constant slot widths. Nor do any have fasteners with a bolt holding capacity equivalent to the fasteners used in standard channeled structural members, and the capacity of being used in channeled structural members having an inside depth clearance less than the overall thickness of the fastener.